The ‘Logic’ of Sherlock Holmes

It’s always struck me that Intelligent Design creationists always seem to fall into a hole of illogic. Essentially, they will argue that a particular biological feature, (examples such as bacterial flagella, the vertebrate immune system, and the origin of life spring to mind) are complex, have a cursory investigation of what is known about those case…then pronounce they cannot have come about by natural causes hence an intelligent designer (aka god) must have done it.

This in many ways reflects one of the classic quotes of the fictional (let us remember) detective Sherlock Holmes.

“When you dismiss the impossible, whatever you have left, however improbable, is the answer.”

There’s a rather nice discussion of this piece of ‘logic’ over by Dave Gamble at the Skeptical Science blog: Beware The Logic of Sherlock Holmes. Essentially, it’s all very well applying such reasoning to a murder within a room with locked windows and doors, but in the real world of scientific research (as opposed to the fantasy world of Intelligent Design), it’s very difficult to rule that, for example, further detailed hypotheses concerning the origins of life may surface through conventional scientific approaches. Dave observes that one should always apply the following:

Are all the other options truly “impossible”?

Perhaps the very premise itself is wrong

In fact have you truly eliminated all other possibilities, is it not more possible that there is a simpler alternative that you have not yet considered?

To invoke an invisible magic designer to explain a bit of biology while denying that science may ultimately identify a plausible (or, dare I say it, demonstrable) explanation is nothing more than an elaborated ‘God of the Gaps’ argument (Intelligent Design creationism’s much vaunted “inference to the best explanation”). We saw this strategy shot down in flames at the Dover trial. And for ID creationists to claim an intelligent magic designer is the best explanation for the origin of life is just the same: scientific investigation has led to several hypotheses for origins of life. Based on evidence from chemistry and physics, and on what is know of prebiotic conditions on Earth, surely there is more going for those scientific hypotheses than a religiously motivated cop-out?